A Fresnel [fruh-nel] lens was originally developed by French physicist Augustin-Jean Fresnel for lighthouses. The design enables the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. Compared to conventional bulky lenses, the Fresnel lens is much thinner, larger, and flatter, and captures more oblique light from a light source, thus allowing lighthouses to be visible over much greater distances. The first Fresnel lens was used in 1823 in the Cordouan lighthouse, north of Bordeaux; its light could be seen from more than 32 km out.
The Daily Omnivore 
Leave a comment